The objectives of this multicenter, randomized trial is to assess the participation rate achievable through two different screening strategies (Computed Tomographic Colonography-CTC and sigmoidoscopy-FS), to compare detection rate of colorectal cancer (CRC) and advanced adenoma of tests and to evaluate their costs. The role of Computer-aided detection (CAD) for CTC screening will be also assessed. The trial involves 10 Italian centers located in the Piedmont Region and in Verona. Residents aged 58-60 years in those districts are target for recruitment. Exclusion criteria include: previous diagnosis of cancer or adenoma; family history or hereditary syndromes; personal history of inflammatory bowel disease; patients screened by colonoscopy or FOBT within 2 years; severe disease.